Apparatus for manufacturing gas.



H. L. DOHERTY. lAPPARATUSHJRMANUPAGTURING GAa APPLICATION FILEDAPR.7,1909. y

- Patented N0v.5, 1912.

4 SHEETS-SHEBT 1.

A@ MMM COLUMBIA PLANOQRAPH co., WASrjINGTUN. D. c.

H. L. DOHERTY.

APPARATUS PORMANUPAGTURING GAS.

APPLICATION FILED APR.7,1909.

Patented Nov. 5, 1912;

4 SHEETS-SHEET Z.

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Patented Nov. 5, 1912.

4 SHEETS-SHEET 3.

Lu BIA PLANOURAPH Co..WAsH|Nu 0N D c H. L. DOHERTY.

APPARATUS FOR MANUFACTURING GAS. APPLIGATION FILED APR.7,1909.

4 SHEETS-SHEET 4.

WIT/VESSES: INI/ENTO? l Henry LDozery g MW By l M W 70E/vf y dDLuMBlAPLANQGRAPH c'o.,wASHxNuToN. D. c.

Patented Nov. 5, 1912.

HENRY L. DOHERTY, 0F NEW YORK, N. Y.

APPARATUS FOR MANUFACTURING GAS.

Loaaaoa.

Specicaton of Letters Patent.

Patented Nov. 5, 1912.

Application led April 7, 1909. Serial No. 488,377.

1'0 all whom 'it may concern:

Be it known that I, HENRY L. Doi-IERTY, a citizen of the United States,residing at New York city, in the county of New York and State of NewYork, have invented new and useful Improvements in Apparatus forManufacturing Gas, of which the following is a specification.

My invention relates to apparatus for manufacturing gas and particularlyto that kind of apparatus in which a combustible gas is formed bysubjecting fuel in a deep bed to combustion by a limited supply of air.

This Vapplication claims the apparatus shown and described in anapplication for Letters Patent Serial No. 488376, led April 7th, 1909,on the process involved in the invention.

The objects of my invention are the furnishing of a means, whereby, inapparatus of the kind mentioned, the freshly charged fuel may besubjected to an igniting :and carbonizing temperature immediately afterbeing charged into the producer, the volatile hydrocarbons distilledfrom the fuel', subjected to a sufficient temperature to fiX them aspermanent gases, by causing them to pass through a considerable depth ofincandescent fuel, and the entire bed of fuel in the producer maintainedin an act-ive gasifying condition. I attain these objects in the hereinrevealed process and by the herein described apparatus by taking o thegas from the producer belowI the surface of the fuel bed, preferably ator near the middle thereof, and by sub'fjecting. .the freshly chargedfuel to the action of a iiame of producer gas.

In the drawings, Figure 1 shows a ver tical section through theapparatus taken on a vertical plane through the line A A of Fig. 2. Fig.2 is a plan of the apparatus; Fig. 3, a cross-section of the recuperatoron a vertical plane through the line D D of Fig. 1. In Fig. 4, I show ahalf plan of a slightly modified form of the producer of the apparatusin which the gas take off pipes are located in a vertical position inthe producer instead of passing through the j sides thereof. Fig. 5 is asection of the same on a vertical plane through the line E E of Fig. 4.

In t-he drawings 1 is the gas producer, 2 a combined recuperator andevaporator, 3 an eXhauster of any common type, 4 the shell of theproducer, 5 the fire brick lining and 6 the arch or dome thereof.

7 indicates the fuel chamber of the producer and 8 the upper part of thefuel chamber unoccupied by fuel which in this case is utilized as acombustion chamber in which a portion of the gas made is burned asdescribed below.

9 is the charging hopper of the producer, 1() the bell closing thebottom of the hopper and actuated by a lever mechanism 11, 12 the coverof the charging hopper.

13 indicates the gas oiftake pipes which are connected with the commonbustle pipe 15.

14 indicates dampers for regulating the draft through the pipes 13.

16 is a pipe or conduit leading the producer gas from the bustle-pipe 15to the gas distributing flue 18 of the recuperator 2 and is providedwith a valve 17.

19, 20 and 21 are three iiues opening out of 18 and affording passagefor the hot producer gas through the recuperator.

22 is a crossfflue connecting the discharge ends of 19, 20 and 21 anddelivering the gas to the suction line 23 of the eXhauster 3.

24 is the discharge pipe of the eXhauster provided with a valve ordamper 25, 26 a pipe opening out of 24 below the valve 25 and leading aportion of the gas back to the gas bustle-pipe 27. Opening out of 27 area number of short pipes 28 passing through the tubes of the burners 29,these latter having air-dampers 30. Valves 63 on 29 serve to regulatethe supply of gas to the burners.

32, 33 and 34 are the air `Hues of the recuperator 2 located in andenveloped by the gas iiues 19, 20 and 21 respectively. The inlet ends`0f 32, 33 and 34 are provided with dampers 31 which serve to controlthe air supply for the producer, the outlet ends Aof the air flues openinto the cross pipe 35,

which has a pipe or conduit 36 having a valve 58 opening out of it andconducting the heated air from the recuperator to the twyer 37 of theproducer. This twyer has a hood or cover 38 which prevents the entranceof ashes into it.

9 indicates poke holes located in the top of the producer and providingaccess to the fuel bed thereof. 40 indicates a number of similaropenings in the sides or shell of the producer for the purpose ofbarring down the fuel bed when required.

41 is the ash door of the producer.

42, 43 and 44 are water ipes having four tiers of branch-pipes num ered48, 49 and 50, sets of valves 51, 52, 53 and 54 respectivelycontrolling` the flow' of water therethrough.

55 indicates the metal shell of the recuperator, 64 the refractory wallsthereof, 56 the refractory backing of the doors covering the ends of thegas flues.

`60 and 61 are division walls which together with the arches 59 form thegas flues 19, 20 and 21.

57 are arches thrown across between the vertical dividing walls andserving to support the sections of the air tlues 32, 33 and 34.

62 indicates refractory linings or tubes which are inserted into such ofthe metal flues as are subjected to a high temperature with a view ofpreventing the collapse of the'said metal tubes while they are softenedunder the influence of the high temperature.

The general construction and arrangement of the recuperator is asfollows: It consists as mentioned of a metal shell 55, having openingsclosed by covers 0r doors 55 opposite the ends of each couple ofsections of gas flues 19, 20 and 21. This shell has a thick inner wallof fire brick 64 and the inclosed space is divided into threecompartments by the partition walls 60 and 61. These compartments aresubdivided horizontally by the partit-ions 59 so as to form what is ineffect a continuous return bend flue of each compartment. Thesepartitions 59 are preferably formed of special tiles supported by thewalls 64, 60 and 61. These partitions 59 are interrupted alternatelyfront and back so as to leave openings establishing communication on theone hand with the section or sub-flue above it and on the other with theone below it. The upper tier of sub-fines open out of the cross iue 18,and the lower tier opens into the cross flue 22. There are thus formedthree parallel returnbend iues for the gas, which receive the gas fromthe conduit 16, and after conducting it through the recuperator,discharge it into the flue 22 leading to the eXhauster.

Within and enveloped by the flues 19, 20 and 21 are the air ues 32, 33and 34, which consist of sections of metal pipes connected by Ts 65 insuch a way as to form three continuous return-bend flues. The lowertiers of these flues have the water connections mentioned above, for thepurpose of supplying` water to them and dams 66 which insure a shallowlayer of water being maintained in the flues. When the supply of waterto any flue is greater than the amount of evaporation therein the excesssimply runs over the dam 66 and thence down the sides of the connectingT to the section next below. Any excess supplied to the lowest tier runsto waste through the waste pipes 45, 46 and 47. Between the Ts 65, andthe doors 55 is a removable or dry wall 56 which prevents the hightemperature in the interior of the recuperator being communicated to thedoors 55, but, which can be easily removed when the recuperator is notin use for the purpose of repairing or replacing the sections of t-heflues 32, 33 and 34 when necessary. The outer ends of the lowestsections of 32, 33 and 34 are provided with dampers or registers 31,which control the flow of air to the llues. The upper sections of 32, 33and 34 connect with the cross flue 35 which as above mentioned,discharges the air to the producer through the pipe 36.

The method of operation is as follows: A bed of incandescent fuel havingbeen built up in the producer in the customary manner, water is run intothe lower tiers of the air iiues 32, 33 and34 in recuperator 2, throughthe connections provided for that purpose, the dampers 31, valves 14,17, 58 and 25 are opened, all poke holes and ash doors closed, and theeXhauster 3 started. This acts to draw 0E the gas from the producerthrough the off-take pipes 13, conduit 16, and flues 18, 19, 20, 21, 22of the recuperator and the suction pipe 23 and discharge it through thepipe 24 to the point of use or to a storage holder where one is used. Atthe same time air is drawn in through the dampers 31 and passes throughthe air flues 32, 33 and 34 of the recuperator in a path parallel butopposite in direction to the travel of the hot producer gas at the sametime passing through the recuperator. This hot gas enveloping and incontact with the said air fines gives up to the air and water in saidflues the greater portion of its sensible heat.

In order to secure the highest practicable transfer of heat from the hotproducer gasto the draft current for the producer, it is advisable toperform the evaporation as low down in the recuperator as possible. For

this reason, the supply of water to the fluesV is so regulated that thewater space in the lowest sections is always maintained full of water.For example, ifv the evaporation from two tiers of sections issufficient to supply the requisite quantity of water, I run the waterinto second tier from the loottom of the recuperator in suflicientquantity to supply the evaporation and permit a slight drip from theoverflows of the lowest sections. If I wish to increase the quantity ofwater vapor that I am furnishing to the producer I open the valve 52 tothe proper degree and close the valves 53. If the evaporation from threetiers of pans is not sufficient, I supply the water to the upper tiersby openingr valves 51 and closing the valves 52, 53 and 54.

It is evident that I may if, I prefer, furnish to each individualsection its own independent supply of water, but I prefer instead tosupply the entire quantity required for each flue to the uppermostsection in use allowing the sections below to be supplied by theoverflow of the ones above. The evaporated water mixes with and isabsorbed by the air current passing through the flues. I/Vhen the draftcurrent enters the upper sections of the flues, the mixed air and watervapor is highly superheated. In ordinary Working, the producergas entersthe recuperator at a temperature of about 1500o F., and theair-waterwapor current leaves it with a temperature of between 1200 and1300O F. This draft current passes through the pipe 36 and twyer 37 intothe fuel bed of the producer. The carbon of the fuel being in a state ofincandescence combines with the oxygen in the draft current in the lowerlayers of the fuel bed to form principally carbon dioxid, according tothe reaction.

(a.) CZ-l-2O2z2CO2.

Part of the water of the draft current probably reacts with the carbonof the lower fuel layers also to form carbon dioxid, at the same timeset-ting free its hydrogen, according to react-ion (t.) oarrgozaooing.

It is probable that a considerable proportion of the oxygen of the airburns directly to carbon monoxid according to the equation A portion ofthe water may also react to form carbon monoxid and hydrogen directlyaccording to reaction reaction (e.) 2CO2+C2=4CO- The greater part of thewater of the draft current is also here disassociated to form carbonmonoxid and hydrogen according to reaction After the exhauster has beenstarted, the valves 63 are opened, permitting a portion of the producergas discharging through 24 to pass back to the producer above the fuelbed thereof. The dampers 30 are opened and the gas and air enteringthrough 29 burns. The burning producer gas raises the chamber 8 to acomparatively high temperature. When a fresh charge of coal isintroduced into the producer it is immediately, therefore, subjected toa carbonizing temperature. Its volatile matter rapidly distils olf and,in passing through the upper portion of the bed of incandescent fuel,the hydrocarbons are cracked and converted for the most part, intopermanent gases. .By admitting the proper excess of air through t-hedampers 30, a greater or less proportion of the distillation gases fromthe raw coal and also some of the fixed carbon of the latter may beburned if desired. In fact, I prefer to sustain the temperature of theupper part of the fuel bed (above the line B B) in part, by such acombustion.

In my present invention the upper portion of the fuel bed, above theline B B is, without the influence of the flame of burn ing producer'gas, subjected to practically the same conditions as the upper portionof the fuel bed in a down draft producer. Without the flame of burningproducer gas the upper part of the fuel bed (above the line C C) wouldbe comparatively cool, since allV the heat that it would receive wouldbe such as would be conducted back against the draft current entering atthe top. The freshly charged fuel would, therefore, simply lie on top ofthe burning fuel, being subjected only to the slow carbonizing action ofthe heat received from the burning fuel below. It would be only when ithad dcscended to the zone of active combustion that it would be actuallycarbonized and ignited. In the type of producer which I have hereinshown, this distillation of the volatile hydrocarbons of the coal wouldtake place so far down in the fuel bed (about 10 inches be low thesurface) that they would be subjected to only a very short travel incontact with the incandescent carbon. The result would be that aconsiderable proportion of such hydrocarbons would pass olf with the gasas vapors and be condensed in the recuperator, in this case (or inwhatever form of cooler might be used in others) resulting in a gradualstoppage of the apparatus and lowering of its efciency due to the tarrydeposit-s formed therein. By burning a portion of the gas made incontact with the latest charge layers of fuel, I avoid, for the mostpart, such passage of hydrocarbon vapors through the fuel bed and keepmy recuperator almost entirely free from tar.

i the burning gas or coal in passing through the incandescent carbonreacts therewith according to reaction (e.) 2CO2+C2:4CO.

This reaction is a heat absorbing` or endothermic reaction, as much heatbeing rendered latent in the dissociation of the carbon dioxid as wasliberated in the combustion of the carbon monoXid from which it wasformed. The water formed by the combustion cf the hydrogen of theproducer gas, according to the reaction anogzaiao.

is also dissociated by passingthrough the incandescent carbon, accordingto reaction (CZ), the same amount of heat being, of course, renderedlatent in its dissociation as was developed in the combustion of thehydrogen from which it was formed. I, therefore, do not lose any heatfrom the system by thus returning a part of the gas to the producer andburning it therein, save such as is lost by conduction from the top andsides of chamber 8. The heat which is developed by the burning of theproducer gas is reabsorbed again in a useful form in reaction (c).

The net result of this device is, therefore, that I am taking heat fromthe interior of the fuel bed where there is a surplus and restoring itto the surface layer thereof in which there is, ordinarily, nocombustion.

I thus keep the entire bed of fuel in a reactive condition.

In the operation of a gas producer the depth of the fuel bed is limited,practically by the resistance which the bed offers to the passage of theblast current. Aside from this restriction, the greater the depth offuel in a reactive condition, the greater is the amount of carbon thatmay be gasiiied per square foot of grate surface. Now, since by mydevice I keep the entire bed of fuel at a temperature sufficiently highto permit the carbon to react freely with the chemically activeconstituents of the draft current, I

vam securing the Greatest oossible ca aacit for my producer. Although Iam returning cooled gas to the upper part of the producer, I do not loset-he sensible heat which it carried out of the producer because I amrestoring suoli heat through the medium of the air current supplied tothe lower part ofthe fuel bed.l I use the cooled `gas owing to the factthat it is under pressure, and, therefore, does not require any movingmechanism to re-introduce it into the producer. Were I to use the hotproducer gas, it is manifest, that I would have to `provide anadditional blower or injector to re-in troduce the hot gas into theproducer, since, even if I were working the producer under pressureinstead of suction, the gas passing through the off-take would, ofnecessity, be under a lower pressurelthan would exist in the chamber 8.

Theoretically, the proper conditions to maintain in a producer are theones which will give the greatest possible reproduction of the heat ofthe original fuel in an available form in the apparatus in which the gasis subsequently burned. There are however important practicalconsiderations which modify the proper theoretical conditions in theproducer in practice. For instance, the clinkering of the ash of thefuel when a high temperature is maintained in the producer, makes itvery difficult to operate the same and entails great irregularity, wearof the producer, and heavy labor in its operation. For these reasons, itis desirable in practice to maintain the temperature of the fuel bedbelow the point at which the ash of the fuel used will clinker. In mypresent invention, I secure this temperature control, by regulating theamount of Water vapor in the dra-ft current supplied to the producer, inthe manner hereinbefore eX- plained.

By working part of my fuel bed on a down draft, and the other part on anup draft, it is readily seen that I am enabled to use nearly double thedepth of bed that may be used in the ordinary type of gas producer. Thismeans that for the same grate area I can gasi nearly twice as muchcarbon.

In Figs. 4 and 5 I have shown a slightly different form of apparatus inwhich the gas take-offs are inserted vertically through the top of theproducer. In this arrangement there is the advantage that there is notendency to increase the draft up the sides of the producer such asobtains in the ,previous arrangement. The arrangement is, however, lessdesirable in other respects and I regard the first arrangement shown asbeing the preferable one. It is obvious, however, that the modiiicationis one that does not in any 'sense change the nature of my invention. Inthis modification the different parts have the same functions as havethe parts designated the same numbers (without the primes) in thepreceding figures.

What I claim is: f

l. In a gas producing apparatus the combination of a gas-producingchamber, a plurality of burners arranged in the wall of said chamber,each of said burners having a passage for gas and enveloping said gaspassage a passage for air, a. damper for regulating the admission of airto said air passage and a valve for regulating the ad mission of gas tosaid gas passage, a bustlepipe connecting said gas passages, means fo-rcharging fuel into said chamber, passages for withdrawing producer gasarranged around the periphery of said chamber, a bustle-pipe connectingsaid gas passages, and dampers in said gas passages for regulating theflow of gas therethrough.

2. In gas producing apparatus, the combination of means for carbonizingthe fuel charged into said apparatus, said carboniz- 'ing meanscomprising a plurality of gas burners arranged to divert a flame of burring gas upon the upper surface of the fuel bed in said apparatus toproduce an upper ignited layer of said fuel and combustible gas, meansfor introducing a combustionsupporting draft current into the lower partof said fuel bed to produce a lower ignited layer of said fuel andcombustible gas, and means for withdrawing the gas produced in saidapparatus from a zone intermediate between the said upper and lowerignited layers of said fuel bed.

3. In combination, a gas producer adapted to contain a comparativelydeep bed of fuel, means for burning a portion of the gas made in saidgas producer in contact with the latest charged layer of fuel in saidproducer, said gas-burning means comprising in combination a pluralityof dampered air passages and a plurality of valve-controlled gaspassages, a heat recuperator for heating air and generating water vaporby means of the sensible heat of gas withdrawn from said gas producer,means for introducing the said heated air and water vapor into the lowerpart of the fuel bed in said gas producer, and means for withdrawing thegas made in said gas producer from the interior of the fuel bed of saidproducer.

4. In combination, a fuel chamber adapted to contain a comparativelydeep bed of fuel,

a plurality of gas burners in the upper part of said chamber, each ofsaid burners comprising one or more passages for gas and one or morepassages for air and means for regulating the flow of fluid through saidgas and air passages, said burners being adapted to maintain an upperignited layer of fuel in said fuel bed, means for maintaining a lowerignited layer of fuel in said fuel bed, one or more gas olf-takepassages located at approximately the middle Zone of said fuel bed andmeans for making said fuel bed accessible for working the fuel in thesame.

5. In combination, a gas producer, said gas producer comprising meansfor intro` ducing a portion of the gas made therein and air in contactwith the latest charged layer of fuel in said gas producer, whereby thesaid fuel is subjected to destructive distillation, means forwithdrawing the gas made in said gas producer from the interior of thefuel bed therein and conveying said gas to a recuperator, a recuperatorfor heating air by the sensible heat of the gas from said gas producer,and means for introducing the air heated in said recuperator into thelower portion of the fuelbed in said gas producer.

6. In combination, a gas producer, said gas producer comprising a fuelchamber, a plurality of burners adapted to burn gas in contact with thelatest charged layer of fuel in said fuel chamber, a plurality o-fpassages located at approximately the middle Zone of said fuel chamber,whereby the gas made therein may be withdrawn fro-m the interior of thefuel bed therein, means for introducing heated air and water vapor intothe lower portion of said fuel bed, a recuperator for heating the saidair and generating the said vapor by the sensible heat of the producergas from said gas producer, and a conduit for conducting the saidproducer gas from said gas olf-takes to said recuperator.

7. In a gas-producing apparatus the com-- bination of a gas-producingchamber, a plurality of burners arranged in the wall of said chamber,said burners each havinO u n 2: passage for gas and enveloping said gas.passage a passage for air, a damper for regulating the admission of airto said air passage and a valve for regulating the admission of gas tosaid gas passage, a bustle pipe connecting the gas passages of saidburners, a passage connecting said bustlepipe with the discharge pipe ofan exhausterblower, an eXhauster-blower, passages for withdrawingproducer gas arranged around the periphery of said chamber, abustle-pipe connecting said gas passages, dampers in said gas passagesfor regulating the flow of gas therethrough and a passage connectingt-he last of said bustle-pipes with t-he suction pipe of saideXhauster-blower.

8. In a gas producer, the combination of a fuel chamber, an ash chamber,means for charging fuel into said chamber, a plurality of gas burnersarranged around the periphery of said chamber near the upper portionthereof, said burners comprising passages for gas and enveloping saidgas passages, passages for air, and means for regulating the flow of gasand air through the respective passages a bustle pipe connecting saidgas passages, a twyer for introducing a current of heated air and steaminto the lower part of said fuel chamber, a door for withdrawing ashfrom said ash chamber, a plurality of poke-holes located in the top ofsaid fuel chamber, a plurality of pokeholes arranged around theperiphery of said fuel chamber at approximately the upper Signed at NewYork city, in the county of portion of the ash zone of said fuel oham-New York and State of New York, this 31st 10 ber, a plurality of gaso-take passages arday of March, 1909.

ranged around the periphery of said fuel chamber, at approximately themiddle Zone HENRY L DOHERTY' of the fuel bed therein, dampers in saidoff- Witnesses:

take passages, and a bustle pipe connecting LoUIs F. MUs1L,

said off-take passages. l C. B. GILBERT.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents, Washington, I). C.

